Parallel motion mechanism



March 28, 1967 HEINZ-GNTHER MLLER VO M HAGEN PARALLEL MOTION MECHANISMFiled Jan. 19, 1965 =u IIIIIIIIIIlllllnllllll'llllllllllIllllll INVENTORHemi-@lumen Mlue Van [MGM United States Patent Ofiflce Paten-ted Mar.2S, 1967 s claims. (ci. 24e- 1885 The present invention relates toimprovements in parallel motion mechanisms, and more particularly to apiece of furniture, such as a two-legged table, wherein one part, i.e.the table plate, is to be vertically reciprocated in relation to a fixedsupport. Other types of furniture which may advantageously use thisimproved parallel motion mechanism include benches, chairs and the like,barroom furniture, etc.

Various lifting mechanisms have been used in furniture wherein one partis to be raised in relation to another part, including Bowden cables ormotors, such as hydraulic or pneumatic motors, but conventionalapparatus has been expensive and/ or unstable.

lt is the primary object of this invention to provide a simple andexceedingly stable parallel motion mechanism useful in furniture whereinone part is to be reciprocated in relation to another part.

This and other objects are accomplished by constructing the fixedsupport as a stable framework forming a first bridge system and thefurniture or other part reciprocatingly movable in relation to its fixedsupport as a like stable framework forming a second bridge system, aparallel motion linkage means interconnecting the two bridge systems.

According to the invention, the first bridge system includes twosubstantially parallel, elongated pillars and the second bridge systemincludes two elongated supporting columns mounted for reciprocatingmovement in the axial bores of the pillars, parallel transverse strutsrigidly interconnecting the telescoping pillars and the columns,respectively.

ln accordance with one preferred embodiment, the parallel motion linkagemeans is a scissors having two links. Each link has two endsrespectively linked to the two bridge systems and a pivot intermediatethe link ends pivotally connects the two links of the scissors. However,other parallel motion linkage means may be used between the two bridgesystems.

According to another preferred embodiment, brake means is mounted ononly a single column to cooperate with a suitable lifting mechanism forpermitting reciprocatingly moving the other part in relation to itsfixed support upon release of the brake means, the parallel motionmechanism moving the other column in parallelism, and engagement of thebrake means between the column and the pillar maintaining the movablepart at any desired level.

The above objects, advantages and features of the present invention willbe more fully understood by reference to the following detaileddescription of one embodiment thereof, taken in conjunction with thesingle ligure of the accompanying drawing.

In the drawing, the invention has been illustrated in connection with atable supported on two legs. The table is shown in a side view, partlyin vertical section, and comprises two substantially parallel, elongatedpillars 1 rigidly interconnected by a first transverse strut 2, thepillars and the strut 2 constituting a first bridge system. Twoelongated supporting columns 4 are mounted for reciprocating movement inthe axial bores lof the pillars, the supporting columns being guided forparallel movement in respect of each other by roller bearings 3interposed between the telescoping pillars and columns. The table plate15 is the furniture part carried by the supporting columns in theillustrated embodiment of the invention, for reciprocation in respect ofpillars 1. A second transverse strut 5 rigidly interconnects thesupporting columns 4, 4 and these columns constitute a second bridgesystem with the strut 5, strut 5 being parallel to strut 2.

The two rigid bridge systems are guided for movement parallel to oneanother by a parallel motion linkage means which interconnects the tw-obridge systems. The illustrated linkage means is a scissors having links7, 7. Each link 7 has two ends respectively linked to the two bridgesystems. A pivot 10 intermediate the link ends pivotally connects thetwo links to each other.

As shown, one of the ends of each link 7 is linked to a fixed pivot 8and 9 on a respective one of the transverse struts. The other end ofeach link carries pivot 11 and 12 moving in slot 13 and 14,respectively, in struts 2 and 5, the slots being parallel to the struts.

This parallel motion mechanism makes it impossible for the twotransverse struts to move out of parallelism with each other, i.e. forone side of the table top to be lifted higher than the other side whenthe table top is raised. This, on the other hand, makes it possible touse an actuating means for reciprocatingly moving the columns 4, 4 inthe axial bores of the pillars mounted only in a single table leg. Theparallel motion mechanism transmits the lifting or lowering motionautomatically to the other leg since the stmt 5 of the second or movingbridge system is moved in parallel to the fixed strut 2 of thestationary of first bridge system.

Raising and lowering of the table top is eected in the illustratedembodiment by releasing a brake means which is designed to hold thecolumn 4 at a given level in its pillar 1 of a single leg, and then toengage the brake again when the column has been vertically moved to thedesired level. The lowermost position of reciprocable column 4 in thisone leg is determined by a transverse abutment 24 mounted on the pillar1 of this leg, which abutment supports the lower end of column 4 in itslowermost position.

The brake means comprises brake shoes 16 mounted on the radiallyexpansible lower end of the one column 4 and frictionally engageablewith the one pillar 1. In the illustrated embodiment, the column is alsotubular and the radial expansion of the lower end thereof is attained byslitting this lower end.

The brake actuating means includes a rod 6 having an upper end and alower end, the rod being axially reciprocable within the tubular column4. A conical element 17 is carried by the lower rod end and taperstowards the lower rod end, the conical element having an axial borereceiving stud 25 mounted on abutment 24 and serving as a guide supportfor the element during reciprocation. Ball bearings 18, 13 are arrangedaround the conical element for attaining radial expansion of the slittedlower end of column 4 by reciprocation of the conical element, i.e. bymoving it upwardly to press the balls outwardly.

The means for reciprocating the rod illustrated herein includes theoperating handle 23 mounted on lug 21 adjacent and underneath the tableplate 15, the lug being mounted on, and extending radially from, the oneleg column 4. The handle has an axle extending perpendicularly to theleg axisand which is rotatably journaled in a bearing hole in the lug.The handle axle has a cam 22 keyed thereto and the cam engages camfollower means in catch 21, this cam follower means being a curvilinearcut-out in the catch and the cam extending into this cutout. The catchis pivoted to lug 21 at 26 and has a nose 19 engaging the annular groove20 in the upper end of rod 6, Turning the handle 23 rotates the handleaxle and the cam 2d keyed thereto, thereby pivoting catch 2l and axiallyreciprocating rod 6 for engagement or disengagement of the brake means.

As seen in the drawing, when the handle is moved to the right, rod 6 israised, the errpansible end of column 4 is expanded and the brake meansengages the inner Walls of pillar i to hold the table plate a desired,vertically adjusted position. When the handle is turned leftwards, therod is lowered, the tapered end cconical element J7 is adjacent ballsand the lower end or column el is permitted to return to its restposition, thus removing tie brale shoes from frictional engagement withthe inner walls of the pillar so that the column may be freely movedvertically in the pillar.

This brake mechanism is more cla .led in my copending application Ser.tiled concurrently herewith.

While the present invention has been described and illustrated inconnection with furniture, and more particularly a two-column table, itwill be clearly understood that tr e parallel motion mechanism hereinshown may be used in other pieces of furniture and equivalent devices,Where it is desired to ettect straight-line motion of one part inrelation to fixed part, and that various parallel motion linkage meansas well as a variety of actuating means may occur to the skilled in theart without departing from the spirit and scope of this invention asdehned by the appended claims.

claim:

Il. A piece of furniture comprising (a) two substantially parallel,elongated pillars, each pillar deiining an axial bore,

(b) a rst transverse strut rigidly interconnecting the two pillars,

(l) the pillars and strut constituting a first bridge system;

(c) two elongated supporting columns mounted for reciprocating movementin said axial bores,

(d) a part of a piece of furniture carried by sai-:l supporting columnsfor reciprocation in respect of said pillars,

(e) a second transverse strut rigidly interconnecting the fullydescribed and No. 426,629,

it two supporting columns and parallel to the lirst strut,

(2) the supporting columns and the second trans- Verse strutconstituting a second bridge system;

(t) a parallel motion linkage means interconnecting the rst and secondbridge systems;

(g) brake means mounted on a single one of the supporting columns forperrc ing temporary retention of said one column at a` desired verticallevel upon engagement of the brake means and reciprocating movement ofsaid column upon release of the brake l. as;

(h) ans for actuating the bralte means from outside said one column,said means including (3) a rotatable operating handle positioned belowsaid part of the piece of furniture, whereby release of the bral'e meansby the operating handle causes reciprocating movement of said column;and

(i) roller bearings interposed between the telescoping pillars andcolumns.

The piece of furniture defined in claim El, wherein the parallel motionlinkage means is a scissors having two links, each having two endsrespectively linked to said bridge systems and a pivot intermediate saidlink ends pivotally connecting said links.

The piece of furniture dened in claim 2, wherein of the ends ot sacrilirtl; is linked to a fixed pivot respective one of said transversestruts, and the otite end of each linli carries a pivot moving in a slotin res ective one of said struts, the slots being parallel o the struts.

CLAUDE A. LE ROY, Primary Examiner.

R. P. SETTER, Assistant Examiner.

1. A PIECE OF FURNITURE COMPRISING (A) TWO SUBSTANTIALLY PARALLEL,ELONGATED PILLARS, EACH PILLAR DEFINING AN AXIAL BORE, (B) A FIRSTTRANSVERSE STRUT RIGIDLY INTERCONNECTING THE TWO PILLARS, (1) THEPILLARS AND STRUT CONSTITUTING A FIRST BRIDGE SYSTEM; (C) TWO ELONGATEDSUPPORTING COLUMNS MOUNTED FOR RECIPROCATING MOVEMENT IN SAID AXIALBORES, (D) A PART OF A PIECE OF FURNITURE CARRIED BY SAID SUPPORTINGCOLUMNS FOR RECIPROCATION IN RESPECT OF SAID PILLARS, (E) A SECONDTRANSVERSE STRUT RIGIDLY INTERCONNECTING THE TWO SUPPORTING COLUMNS ANDPARALLEL TO THE FIRST STRUT, (2) THE SUPPORTING COLUMNS AND THE SECONDTRANSVERSE STRUT CONSTITUTING A SECOND BRIDGE SYSTEM; (F) A PARALLELMOTION LINKAGE MEANS INTERCONNECTING THE FIRST AND SECOND BRIDGE SYSTEM;